In conventional postal and courier drop off boxes, there is no way to determine whether there are articles in the box without someone physically checking the contents of each box. This results in many unnecessary pick-up stops by postal and courier workers at empty boxes.
Conventional postal and courier drop off boxes are also susceptible to tampering, vandalism and theft, which is usually only discovered by postal or courier workers at the next scheduled pick-up.
In addition, in today's age of terrorism, packages containing explosives, chemical or biological threats can be left in drop off boxes and remain undetected thus posing a threat to persons using the box or situated near it.
Prior art drop off boxes have been proposed which include some security features. One such drop off box is disclosed in PCT publication WO 00/76378 entitled Network Connected Delivery Box Using Access Codes and Method for Providing Same, published on Dec. 21, 2000 and naming Holtkamp et al as inventors. The Holtkamp application discloses a delivery box which includes a communications unit linking the box with a central computer at a delivery box company. The box is equipped with sensors for detecting when items are placed in the box and for monitoring the ambient temperature in the box.
Item placement and ambient temperature data from the sensors is transmitted by the communications unit via a portal interface with a cellular or satellite communications link to the central computer. The box can be integrated through the portal interface with a delivery company's GPS tracking system.
PCT publication WO 97/43935 entitled A Mail Box, published on Nov. 27, 1997 and naming Lateo as inventor discloses a mail box which includes a microprocessor controlled locking system which can be activated in the event of an attempted forced entry into the mail box. A sensor detects the deposit of articles into the box. The box is linked to a monitoring centre by a communications link.
None of the prior art boxes discussed above include sensors for detecting the deposit of hazardous materials in the box. Furthermore, where the security and communication systems in the prior art boxes are battery powered, no power saving functionality is taught.
Thus there is a need for a container monitoring system having a low-power stand-by mode which permits the monitoring system to be operational over extended periods of time.